Members of the Section continue to care for over 100 patients with nephropathic cystinosis. Pre-transplant patients receive oral phos- phocysteamine, which has allowed for maintenance or growth of renal function in these individuals. Six pre-transplant patients were also treated with oral L-carnitine which restored their plasma levels to normal and resulted in normal muscle carnitine levels after approximately 5 years of therapy. Post-transplant patients are studied for their nonrenal complications and are offered oral phosphocysteamine. Cysteamine eyedrops (0.5%) have dissolved corneal crystals in young children and removed the haziness from the eyes of older children. A gene exclusion map has been constructed for cystinosis using CA repeats as polymorphisms in linkage analysis. In other studies, 17 patients with Menkes disease have received daily subcutaneous injections of copper histidine. There has been modest clinical improvement in several patients. Plasma and cerebrospinal fluid neurotransmitter ratios have proven useful for the diagnosis of this disorder. Specific molecular mutations are being pursued in individual patients. Investigations continue into Carbohydrate Deficient Glycopro- tein Syndrome. The carbohydrate pattern of one serum glycoprotein, alpha- 1 antitrypsin, is abnormal in its ratio of N-acetylglucosamine to mannose and of galactose to mannose. This provides a clue into the basic defect in this disorder.